On stage, the famous jazz pianist Thelonious Monk wore a collard-leaf pin in his lapel - an act of solidarity, in the guise of a key Southern food, with his sharecropper roots.

Standing in front of Selma High School the other day, principal Roosevelt Wilson broke with Mr. Monk and proclaimed war on the humble but proud collard, the leafy green usually cooked with lard, and all the other unhealthy Southern foods it evokes.

Wilson is part of a growing crusade to cinch a few notches on the nation's Barbecue Belt. He and others are breaking with the tradition of Southern grub - fried chicken, pulled pork, crawfish pies - not to mention school-lunch pizza and french fries to help stem a national obesity "epidemic."

In black communities across the South, the healthy foods movement is finding converts who want to replace bacon-soaked beans and corn pone with baked chicken and steamed broccoli - all in the name of keeping people, particularly young people, healthy.

But as they do, critics say it undermines a central element of Southern culture - one shared by both blacks and whites. "If you look at the aspects of Southern culture that we ... can celebrate as a joint creation, they are music and food," says John Edge, director of the Southern Foodways Alliance in Oxford, Miss., a group working to to preserve food traditions of the South. These are "byproducts of a multiracial culture, something in which we can take pride, not something we should be ashamed of."

Eating one's way across the South yields a trove of treasure or trouble, depending on your point of view: red link sausages, pig pickins, chicken fried steak, red-eye gravy, even, as at Big Ed's in Raleigh, N.C., "brains with eggs." It's a culture of food tied in part to the provincial survival of the South: collards and other field greens provided the necessary nutrients to a population that, in the early 20th century, had suffered deficiencies from the "Three M diet:" meat, meal, and molasses.

From the fried chitterlings at The Varsity in Atlanta to the fried chicken with gravy at Mama Dip's in Chapel Hill, N.C., it's popular fare - and increasingly controversial in a health-conscious age.

Alabama's Black Belt Action Commission, a group formed to improve living conditions in the state's poorest counties, is among those trying to change dietary habits. It is pushing to replicate Wilson's efforts at Selma High across the state. Last year, the school started doing health screenings on students and brought in older blacks to talk about how their "harmful" food choices impacted their health in later years. That led to a revamp of the cafeteria menu to favor baked foods over fried, as well as the removal of soda and snack machines from the halls.

For Wilson, it's a broader philosophical battle, one backed by top doctors in the state. As a health major in college, Wilson says the causes of problems in his city - recently deemed the "fattest in the state" - are obvious: an older generation cooking rich foods that contribute to obesity and health woes.

He's quick to note that lard-soaked Southern foods are adversely affecting black people more than whites: Statistics show African-Americans gaining weight faster. BlackHealthCare.com, a website devoted to African-American health issues, recently wrote that increased health risks among blacks in the Carolinas and Georgia is rooted partly in "a regional preference for salty, high-fat foods."

In a city that once awakened the country to civil rights issues, it seems everyone from Mayor James Perkins to School Board member John Terry is reevaluating their daily vittles. "We have the obligation to alert students that a lot of your good stuff has got plenty of fats in it," says Mr. Terry, who has had to temper his own consumption of favorite foods: fried chicken, fried catfish, barbecue, and ice cream.

Terry acknowledges that food is hardly the only cause of the city's health issues. "Some of it is also hereditary, and part of it would be laziness, a failure to exercise," he says.

But there's more to this tale of the table. In this historically poor region, food became entwined not just in stories of survival; it became a symbol, to some, of white persecution of blacks. The coining of the term "soul food" in the 1960s was a way to separate foods that originated with slaves and indigenous people from "plantation food." "What we may be seeing today in some African-American responses [away from Southern food] could be influenced by a pejorative association to a plantation diet," says Mr. Edge.

But the problem with Selma High's approach, critics say, is that research is conflicted about what constitutes a proper diet - and what, exactly, the factors are that play into obesity. They concede that rich foods can contribute to weight problems. But the question, really, is whether a traditional diet can be part of a healthy, moderate life style.

"It's particularly unfortunate that communities that might be vulnerable to invidious targeting on these matters get fed, metaphorically speaking, misleading information, like traditional Southern food being bad for you," says Paul Campos, a University of Colorado sociologist and the author of "The Obesity Myth."

Certainly healthy food advocates face an uphill fight in changing perceptions across the South. Take the scene at Arthur Cato's House of Southern Food in Hogansville, Ga., where the waitresses write in Magic Marker on wide pads. The grits come topped with butter. Lots of it. Fried catfish comes out of the kitchen in schools. The smoked sausage is dished out in large proportions.

"This is roots food," says Mr. Cato, wiping his hands on his apron. "I've never eaten anything else. I'm 77 years old, and I'm skinny as a rail."

At the Autagaville Cafe, a cinder-block restaurant in the heart of the Black Belt, Mary Wright shrugs off the food controversy, too. "No matter what we do, we're all going to leave here one day, so we might as well go happy and full," she says.

According to Wilson, the low-fat diet at Selma's gothic-looking high school caused a lot of "belly-achin' " as well. But a year later students are adjusting. Senior Clarence Walker, for one, resisted the idea of baked chicken over fried. Now, he says, "it all tastes pretty good."